Catalysis of the cellulose-cyclic urea reactions by built-in acid groups

ABSTRACT

Sulfonic acid groups in sulfonoethylated cotton act as built-in catalysts for the reaction of cotton with substituted cyclic ureas. The cotton in the acid form did not require an additional catalyst for its reaction in aqueous media with dimethylolethylene urea, dimethylolpropylene urea, dihydroxyethylene urea, and dimethyloidihydroxyethylene urea. The strong acid groups of SE-cotton were more effective than carboxylic or phosphonic acid groups of carboxymethylated and phosphonomethylated cottons of like degree of substitution with each urea.

United States Patent 1 Perrier et al.

[ 1 May 22, 1973 [54] CATALYSIS OF THE CELLULOSE- CYCLIC UREA REACTIONS BY BUILT- IN ACID GROUPS [75] Inventors: Dorothy M. Perrier; Ruth R.

Beuerito, both of New Orleans, La.

[73] Assignee: The United States of America as represented by the Secretary of Agriculture, Washington, DC.

[22] Filed: Mar. 15,1972

21 Appl. No.: 234,960

[52] US. Cl. ..8/129, 8/1163, 8/120, 260/231 A, 260/232 [51] Int. Cl ..D06m 13/20, D06m 15/58, D06m15/72 [58] Field of Search ..8/129, 116.3, 120

[56] References Cited OTHER PUBLICATIONS Daul et al., Textile Research Journal 22, 792-797 (1952) Soignet et al., Textile Research Journal 38, 1143 (1968) Soignet et al., Textile Research Journal 39, 780-787 (1969) Perrier et al., Textile Research Journal 41, 680-685 (1971) Perrier et al., Textile Research Journal 42, 167-171 Primary Examiner-George F. Lesmes Assistant Examiner-James Cannon A ttorney- R. Hoffman and W. Bier [57] ABSTRACT 5 Claims, No Drawings CATALYSIS OF THE CELLULOSE-CYCLIC UREA REACTIONS BY BUILT-IN ACID GROUPS A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

Sulfonoethyl substituents in cotton were used as built-in catalytic sites for reactions of cellulose hydroxyls with N-methylolated cyclic ureas and dihydroxyethyleneurea. Cation-exchange cottons, such as carboxymethylated and phosphonomethylated cotton, were not as effective in self-catalyzed reactions with the cyclic ureas and did not result in improved wrinklerecovery values comparable to those obtained with sulfonoethylated cottons.

It is well known in the prior art that the cellulose hydroxyls will react with substituted cyclic ureas in the presence of a catalyst. Usually these catalysts are added to the reagent solution and padded on to the fabric. Ammonium salts, especially the hydrochlorides of ammonium salts, or metal salts have been used previously to catalyze N-methylol cyclic ureas onto cotton cellulose to produce wash-wear and permanent press garments. Once, however, the solution of the catalyst and the cyclic urea are padded onto the fabric and the fabric dried at low temperature, below 70C, the reaction between the cyclic urea and the cellulose will proceed rapidly on the application of heat or at a somewhat slower rate at room temperature. The possibility of padding the cyclic urea and catalyst on a fabric and then storing it for long periods of time before curing is negated due to the reactivity of the cyclic urea at stor age temperature.

The process described in the instant invention differs from the prior art in that the catalyst is incorporated first as an integral part of the cellulose matrix and thus is separated from the cyclic urea. The fabric padded in this manner will not react appreciably with the cyclic urea during storage at or near room temperature but will react immediately upon curing at high temperatures, i.e., greater than 100C. It is then possible to store the fabrics with the adhered reagent and pendant sulfonoethylated groups at or near room temperature, fashion the fabric into garments and then cure the garment without fear of premature crosslinking the fabric. The garment after curing will have permanent press properties which will maintain a wrinkle free look even after repeated launderings.

in carrying out the preferred process of this invention, ce11ulosic fabric was twice padded to 100 percent wet pickup of a solution which is 0.05 M with respect to the sodium salt of 2-chloroethy1su1fonic acid and 10 percent with respect to sodium hydroxide. The padded fabric was then cured at 125C for 5 minutes. Unreacted reagent was removed by soaking the fabric in dilute acetic acid and washing in tap water. The fabric was then dried at 125C for 5 minutes. To insure that the fabric was completely in the required acid form, it was soaked in 2% 1-1C1for 4 hours. The fabric was thoroughly washed in tap water and then deionized water to remove all traces of HCl. The fabric was then ironed dry and air equilibrated.

The fabric prepared above was then twice padded to a 100 percent wet pickup in an aqueous solution containing weight percent of a cyclic urea selected from the group consisting of dimethylolethyleneurea (DMEU), dimethylolpropyleneurea (DMPU), dihydroxyethyleneurea (DHEU), and dimethyloldihydroxyethyleneurea (DMDHEU), dried at 60C for 7 minutes and then allowed to stand for periods up to 50 days before curing at 160C for 5 minutes.

Cellulosic materials such as cotton, rayon, ramie, jute, and flax and in the form of fiber, yarn, fabric or powder may be used in the process of this invention. The degree of crosslinking in the ion exchanged, powdered, sulfonoethylated cellulose can also be increased by the process of this invention.

The following examples illustrate but do not limit the scope of this invention. All percents are by weight. Breaking strength tests were carried out according to the ASTM Method Dl682-64. Conditioned (dry) wrinkle recovery measured was determined according to the ASTM D1295-67 method and the wet recoveries according to the method described by Fujimoto, R. A., et al., Am. Dyestuff Reporter, 52, 329, 1963.

EXAMPLE 1 Cotton printcloth (x80) was twice padded to percent wet pickup of a solution which was 0.85 M with respect to the sodium salt of 2-chloroethylsu1fonic acid and 10 percent with respect to NaOH, then was cured at C for 5 minutes. Unreacted reagent was then removed by soaking the fabric in dilute (5-10 percent) acetic acid and washing in tap water for 30 minutes. The fabric was then dried at 125C for 5 minutes. To insure that the fabric was completely in the acid form, it was then soaked for 4 hours in 2% HCl and washed thoroughly with tap water, followed by rinsing with ion free water to remove all traces of unbound HCl. The fabric was then dried by ironing followed by air equilibration. The fabric had a sulfur content of 1.3 percent with a dry and wet wrinkle recovery (W+F) of 194 and 198, respectively. The fabric was then twice padded to 100 percent wet pickup of a 10 percent solution of dimethylolethyleneurea, dried at 60C for 7 minutes, and then portions of the fabric were allowed to stand at room temperature for varying times. The following table illustrates the results obtained after time intervals up to 50 days, with and without curing.

TABLE 1 Storage Cured (C) Formal- Wrinkle Recovery Time or Nitrogen dehyde (W+F) Days Uncured Dry Wet 0 U 0.04 0 197 209 0 C 1.49 2.53 274 273 8 U 0.36 0.58 215 231 8 C 1.48 2.40 266 275 15 U 0.60 0.76 224 259 15 C 1.51 2.43 279 263 22 U 0.90 1.53 230 296 22 C 1.58 2.47 272 254 29 U 1.06 1.61 222 277 29 C 1.56 2.05 282 272 36 U 1.10 1.77 222 286 36 C 1.58 2.69 271 2 92 43 U 1.1 1 2.07 214 279 43 C 1.53 2.92 259 280 50 U 1.21 2.12 214 287 50 C 1.58 2.77 274 290 The fabrics had a good hand and maintained their high wrinkle recovery and permanent press appearance through several home-type launderings. It can be seen that the fabric did not attain a high dry recovery (above 250 (W+F))even after 50 days storage. Only after curing at C for 5 minutes, did the fabric attain these high dry wrinkle-recoveries necessary to have a smooth appearance after home-type washing and tumble or EXAMPLE 4 line drying An 80 X 80 cotton printcloth was treated with 2-chloroethylsulfonic acid as in Example 1. The fabric EXAMPLE 2 was padded with 10 percent dihydroxyethyleneurea,

5 dried at 60C for 7 minutes and cured at different tem- An 80 X 80 cotton printcloth fabric was treated as in peratures for 5 minutes. Effect of temperature and time Example 1 except dimethylolpropyleneurea was used of wash on properties of sulfonoethylated cotton as the crosslinking agent. Results are shown in Table 11., treated with 10% DHEU are shown in Table IV.

, Mm, L- 7 LL.

Efieet of Temperature and Time of Wash on Properties of Sulfonoethylated Cotton Treated with 10% DHEU Wrinkle recovery (W+F), deg. Breaking Elonga- Abrasion Wash N, wt. strength, tion, resistance Cure temperature, 0. treatment 2 percent Wet Cond. 1b. percent cycles 3 {Immediate 0 209 187 41 16 351 Delay 0 33 240 207 21 14 733 {Immediate 0 202 187 32 18 355 Delay 0 12 227 216 33 17 612 {Immediate. 0 18 214 188 18 418 Delay 0 27 240 201 24 18 A0 {Immediate 1 24 288 222 30 16 350 Delay"... 1.08 293 230 20 16 324 SE-control 198 194 37 16 298 Specimens were padded with 10% DHEU, dried at 60 C. for 7 min., and cured at stated temperatures for 5 mm.

2 After cure, fabrics were either washed immediately or the wash process was delayed for 6 weeks during which time fabrics were stored at room temperature and humidity.

3 Fabrics received no cure and were stored at room temperature.

TABLE II We claim:

Storage Cured (C) Formalwrinkle Recovery 1. A process for reacting cotton fabric with N- Time Nimge" dehyde (W+F) eth lolat d c clic ureas to ive a fabric with im- Days Uncured (U) Dry We! m y y g 0 U @021 0925 194 210 proved wrinkle-recovery values and improved abrasion o C U76 2-153 267 288 resistance, said process comprises: 14 U 0.694 1.173 217 250 14 C 1.852 244 277 a. padding a cotton fabric with the sodium salt of g: g 3 3g; 13;? 5 2-chloroethylsulfonic acid; 42 0 0:86! 1:761 227 291 3 curing the fabric from 42 C 1.197 2.338 273 289 c. treating the cured fabric from (b) with a cyclic a sel ct from the rou consistin of dime- EXAMPLE 3 e ed g P g thylolethyleneurea, dihydroxyethyleneurea, dime thylolpropyleneurea, and dimethyloldihydroxye- 0 thyleneurea,

d. curing the fabric from (c),

2. The process of claim 1 wherein the cyclic urea is An 80 X 80 cotton printcloth fabric was treated as in Example 1 except dimethyloldihydroxyethyleneurea was used as the crosslinking agent. Results are shown in Table I".

TABLE III dimethylolethyleneurea.

Storage Cured (C) Fonmb wrinkle Recovery 3. The process of claim 1 wherem the cyclic urea 15 Time or Nitrogen dehyde (W+F) 45 dihydroxyethyleneurea. Days Uncured (U) Dry Wet 0 u 002 0929 139 215 4. The process of claim 1 wherem the cyclic urea IS 0 U 101 257 274 dimeth 101 ro leneurea. 14 U 0.24 0.45 203 228 y P W 14 c 1.12 2.08 296 27s 5. The process of claim 1 wherem the cyclic urea 15 28 U 0.506 0.89 208 252 28 G H6 213 290 26 d1methyloldihydroxyethyleneurea. 42 u 0.57 0.89 208 255 42 c 1.27 2.20 283 280 

2. The proceSs of claim 1 wherein the cyclic urea is dimethylolethyleneurea.
 3. The process of claim 1 wherein the cyclic urea is dihydroxyethyleneurea.
 4. The process of claim 1 wherein the cyclic urea is dimethylolpropyleneurea.
 5. The process of claim 1 wherein the cyclic urea is dimethyloldihydroxyethyleneurea. 